From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4ACCDECAAD5 for ; Mon, 12 Sep 2022 08:45:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229796AbiILIp3 (ORCPT ); Mon, 12 Sep 2022 04:45:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47262 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229681AbiILIpZ (ORCPT ); Mon, 12 Sep 2022 04:45:25 -0400 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 2F501275FD for ; Mon, 12 Sep 2022 01:45:24 -0700 (PDT) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 51F00113E; Mon, 12 Sep 2022 01:45:30 -0700 (PDT) Received: from [172.16.16.241] (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 5301D3F73D; Mon, 12 Sep 2022 01:45:22 -0700 (PDT) Message-ID: <294b8903-393f-7242-a887-6ec6d6fc829e@arm.com> Date: Mon, 12 Sep 2022 10:45:00 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.9.1 Subject: Re: [PATCH 2/4] sched/fair: cleanup loop_max and loop_break Content-Language: en-US To: Vincent Guittot , mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, vschneid@redhat.com, linux-kernel@vger.kernel.org Cc: zhangqiao22@huawei.com References: <20220825122726.20819-1-vincent.guittot@linaro.org> <20220825122726.20819-3-vincent.guittot@linaro.org> From: Dietmar Eggemann In-Reply-To: <20220825122726.20819-3-vincent.guittot@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 25/08/2022 14:27, Vincent Guittot wrote: > sched_nr_migrate_break is set to a fix value and never changes so we can > replace it by a define SCHED_NR_MIGRATE_BREAK. > > Also, we adjust SCHED_NR_MIGRATE_BREAK to be aligned with the init value > of sysctl_sched_nr_migrate which can be init to different values. > > Then, use SCHED_NR_MIGRATE_BREAK to init sysctl_sched_nr_migrate. > > The behavior stays unchanged unless you modify sysctl_sched_nr_migrate > trough debugfs. I don't quite get this sentence. The behavior would potentially change if you change sysctl_sched_nr_migrate before this patch too? > > Signed-off-by: Vincent Guittot > --- > kernel/sched/core.c | 6 +----- > kernel/sched/fair.c | 11 ++++------- > kernel/sched/sched.h | 6 ++++++ > 3 files changed, 11 insertions(+), 12 deletions(-) > > diff --git a/kernel/sched/core.c b/kernel/sched/core.c > index 64c08993221b..a21e817bdd1c 100644 > --- a/kernel/sched/core.c > +++ b/kernel/sched/core.c > @@ -142,11 +142,7 @@ __read_mostly int sysctl_resched_latency_warn_once = 1; > * Number of tasks to iterate in a single balance run. > * Limited because this is done with IRQs disabled. > */ ^^^ Shouldn't this comment be removed as well? > -#ifdef CONFIG_PREEMPT_RT > -const_debug unsigned int sysctl_sched_nr_migrate = 8; > -#else > -const_debug unsigned int sysctl_sched_nr_migrate = 32; > -#endif > +const_debug unsigned int sysctl_sched_nr_migrate = SCHED_NR_MIGRATE_BREAK; > > __read_mostly int scheduler_running; [...]